1. Field of the Invention
The present invention relates to an automobile operation apparatus and method designed for detecting failure of a drive gear selector of an automatic transmission, and more particularly, to an automobile operation apparatus and method capable of operating an automobile having a sport mode when a drive gear of the automobile malfunctions.
2. Description of the Related Art
In general, some automatic transmission vehicles include P, R, N, D, 2 and L gears, and other automatic transmission vehicles include an automatic transmission having a normal mode constituted by P, R, N and D gears and a sport mode manually operated by a gearshift lever.
The automatic transmission having the sport mode includes P, R, N and D gears and up/down switches such as + and − switches. A driver may automatically drive the automobile in a state in which a gearshift lever is in the D gear as a forward shift, or manually drive the automobile by moving the gearshift lever to the sport mode and operating the up(+) or down(−) switch step by step to vary the speed of the automobile.
In the manual gearshift of the automatic transmission, an inhibitor switch detects a shift gear position of the gearshift lever to control a shift pattern appropriate to the P, R, N and D gears, and determines whether a selector switch is in the sport mode or the normal mode in the D gear.
The automatic transmission including the sport mode, as shown in FIG. 1, includes a gearshift lever having a down switch 11 for downshifting, an up switch 12 for upshifting, and a selection switch 13 for detecting whether the sport mode is selected or not.
In addition, a cluster 14 detects the current shift gear to transmit it to a transmission control unit (TCU) 16.
In the sport mode vehicle, gear signals input into the TCU 16 correspond to P, R, N and D gears. In the D gear, an inhibitor switch 15 does not immediately input a D gear signal to the TCU 16 but first determines whether a sport mode selection switch 13 installed between the TCU 16 and the inhibitor switch 15 is switched to a normal mode or sport mode of the D gear.
In the automobile having the sport mode, when there is no signal for P, R, N and D gears and the sport mode selection switch 13 is ON, the TCU 16 determines that the switch 13 is in the sport mode.
In addition, when the inhibitor switch 15 is normal and the sport mode selection switch 13 malfunctions, or when a signal line between the inhibitor switch 15 and the sport mode selection switch 13 is cut such that a selected mode is not input into the TCU 16, the TCU 14 performs determination according to control logic.
When a state in which a signal from the inhibitor switch 15 is not detected, or a plurality of signals are simultaneously detected the control logic allows the TCU 16 to perform control depending on a signal just before the state. Further, after the above state reverts to the normal state, the TCU 16 performs control on the basis of the detection signal.
Therefore, when it is determined that the sport mode selection switch 13 malfunctions according to malfunction determination conditions of the inhibitor switch 15, since control just before the above state is performed, control depending on any one of the P, R, N and D gears is performed.
Meanwhile, Document 1 discloses a “Method for Controlling Automatic Transmission During Fault of Sports Mode Select Switch for Vehicle,” which is shown in FIG. 2.
As shown in FIG. 2, in the method for controlling an automatic transmission during fault of a sports mode select switch for an automobile, while the automobile is moving or stopped, a driver shifts a gearshift lever to a “D” gear and selects a normal mode or a sport mode.
That is, when the gearshift lever is positioned at the “D” gear, the inhibitor switch transmits a “D” gear selection signal to a TCU, and then the select switch is operated to select a normal mode or a sport mode.
When the driver selects the sport mode, the TCU checks whether one of up/down switches is input.
In addition, when it is checked that one of the up/down switches is input, the TCU allows entry into the sport mode such that the driver shifts the gearshift lever up/down. Further, the entry into the sport mode is allowed even though a “D” gear inhibitor switch signal of the gearshift lever is not input. At this time, when P, R and N inhibitor switch signals are input for a certain time, the TCU blocks entry into the sport mode and maintains the normal mode.
In the “D” gear, when the select switch is positioned at the sport mode and the up/down switches are simultaneously input, the TCT determines that the up/down switches are malfunctioning and blocks entry into the sport mode.
That is, entry inhibition conditions of the sport mode are set to the case that the up/down switches are simultaneously input for a certain time in the sport mode, and the case that the up/down switches are input for a certain time while the inhibitor switch signals of the P, R and N gears are input.
In the failure determination control logic, when the driver selects the sport mode and turns on the up/down switches upon failure of the inhibitor switch, the TCU checks the P, R and N inhibitor switch signals. When there is no signal input, the TCU determines that the gearshift lever is positioned at the “D” gear, enters the sport mode, and maintains a normal running state.
In addition, when any one of the up/down switches malfunctions, a sport mode signal of the select switch and signals of the up/down switches are simultaneously input. In this case, the TCU determines that the up/down switches are malfunctioning, blocks entry into the sport mode, and maintains the normal mode.
Further, Document 2 discloses a “Breakdown Control Method When Sports Mode Selection of Automobile Automatic Transmission,” which is shown in FIG. 3.
As shown in FIG. 3, in the breakdown control method when a sports mode selection of an automobile automatic transmission, a TCU resets a timer to determine whether the sport mode is operating normally, and the timer continuously counts a time from a reset point (ST20).
In addition, the TCU determines whether a P gear signal detected and transmitted by an inhibitor switch is input (ST21), and the TCU determines whether a gear signal of the inhibitor switch corresponds to one of P, R, N and D gears or the sport mode (ST22 to ST25).
In steps ST21 to ST25, when at least one gear signal is input from the inhibitor switch, the TCU determines that the inhibitor switch is operating normally and stops failure determination.
Meanwhile, in steps ST21 to ST25, when no gear signal is input from the inhibitor switch, the TCU determines whether there is a signal applied from an up switch or a down switch.
An upshift signal and a downshift signal are applied from the up switch and the down switch, respectively (ST26).
When neither of the upshift signal and the downshift signal is input in step S26, the TCU determines whether the time counted by the timer exceeds a set threshold time (ST27).
When it is determined that the counted time of the timer exceeds the thresholdl time, the TCU returns to step ST21 to repeatedly determine whether a gear signal of the inhibitor switch is output (ST27).
As described above, the threshold time is set to designate a minimum reference time for determining no signal detection of the inhibitor switch.
In addition, when the counted time of the timer exceeds the threshold time in step ST27, the TCU performs gearshift control depending on a prior gearshift stage corresponding to a gear signal last detected by the inhibitor switch (ST28).
Meanwhile, when at least one of the upshift signal or the downshift signal is applied in step ST26, the TCU determines that the gearshift is a first speed to perform gearshift control (ST29).
Further, when the first speed control is performed in step S29, the TCU determines whether the upshift signal or the downshift signal is continuously input by acceleration or deceleration of the driver (ST30).
When the upshift signal or the downshift signal is input in step ST30, the TCU performs gearshift control according to a regular shift pattern (ST31).
However, in the conventional automatic transmission including the sport mode, contact failure of the inhibitor switch and the gearshift lever makes it impossible to drive the automobile. When tension of a cable connected to the gearshift lever is loosened or cut, the gearshift lever cannot be shifted and the automobile becomes undrivable.
In addition, under the condition that a signal from any one of the P, R, N and D gears of the inhibitor switch is not detected, the automobile can be driven by determining that the gearshift lever is positioned at a first speed on the basis of a signal detected from any one gear of the up/down switches of the sport mode. However, when a signal from any one gear of the inhibitor switch is detected, the automobile is disabled. In addition, when only the D gear of the sport mode malfunctions upon signal detection from any one gear, the automobile may be disabled.
Meanwhile, in the technology described in Document 2, when the inhibitor switch signal of the D gear is not detected, the automobile can be driven after the gearshift lever is positioned at the sport mode and then any one signal of the up/down switch of the sport mode is detected. Therefore, when a signal from the D gear and the up/down switches of the sport mode is not detected, the automobile may be disabled.    [Document 1] Korean Patent Laid-open Publication No. 2002-49231 (Jun. 26, 2002)    [Document 2] Korean Patent Laid-open Publication No. 2007-62010 (Jun. 15, 2007)